<!doctype html>

<html>
<head>
    <link rel="stylesheet" href="startcs.css">
</head>


<body>
    <div>选择难度</div>
    <a href="index.html">初级</a>
    <a href="index中级.html">中级</a>
    <a href="index高级.html">高级</a>
</body>

</html>